Do the Orbitofrontal cortex and the Amygdala encode enough information to detect Small Animal Phobia? A binary support vector machine study

Do the Orbitofrontal cortex and the Amygdala encode enough information to detect Small Animal Phobia? A binary support vector machine study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Do the Orbitofrontal cortex and the Amygdala encode enough information to detect Small Animal Phobia? A binary support vector machine study Alessandro Scarano, Ascensión Fumero3, Luca Sarzi Maddidini, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6048417/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Small animal phobia (SAP) is an anxiety disorder characterized by an intense fear triggered by small animals. Existing studies on SAP have primarily used univariate analyses and small, unbalanced samples, leading to inconsistent findings. Many brain structures have been proposed as potential candidates for encoding SAP, including the amygdala, the orbitofrontal cortex, the insula, the cingulate gyrus, the hippocampus, the precuneus, and the putamen. However, no previous study has systematically compared the predictive role of each of these regions to determine which one provides the most accurate classification of individuals with SAP. To address this question, we tested the predictive power of these brain regions associated with SAP. Structural MRI images of 32 individuals with SAP and 90 matched healthy controls were analyzed using multiple Binary Support Vector Machines (BSVM). Our results showed that the most critical regions for classifying SAP, in order of significance, were the orbitofrontal cortex (balanced accuracy = 80.83%), the amygdala (76.15%), the insula (71.35%), and the posterior cingulate (71.25%). However, only the orbitofrontal cortex and the amygdala consistently exceeded chance levels across all additional parameters considered (precision, specificity, sensitivity, and F1-score). In conclusion, this study enhances the understanding of the neural basis of small animal phobia, suggesting new research directions and diagnostic strategies using advanced machine learning methods applied to neuroimaging data. Clinical implications are also discussed. animal phobia machine learning clinical neuroscience amygdala orbitofrontal cortex Full Text Additional Declarations The authors declare no competing interests. This study adhered to the ethical standards of the Declaration of Helsinki and was approved by the Ethics Committee for Research and Animal Welfare of the University of La Laguna, Spain (CEIBA2013-0086). All participants provided written informed consent, in compliance with the ethical guidelines set by the consortium. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6048417","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":416939481,"identity":"113c6541-91be-4f52-9691-4651cbb8ab00","order_by":0,"name":"Alessandro Scarano","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Alessandro","middleName":"","lastName":"Scarano","suffix":""},{"id":416939482,"identity":"ae4977d9-4a22-4b2d-9774-9e4d06f4e0c3","order_by":1,"name":"Ascensión Fumero3","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Ascensión","middleName":"","lastName":"Fumero3","suffix":""},{"id":416939483,"identity":"bd5f72f1-71f8-40fe-ae98-4138191bcad9","order_by":2,"name":"Luca Sarzi Maddidini","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Luca","middleName":"Sarzi","lastName":"Maddidini","suffix":""},{"id":416939484,"identity":"dd9f7da0-25f1-400f-b2c7-b32be4b4cc6a","order_by":3,"name":"Enrico Ruà","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Enrico","middleName":"","lastName":"Ruà","suffix":""},{"id":416939485,"identity":"8b853494-9f88-40b8-9f1d-bbae073678db","order_by":4,"name":"Francisco Rivero","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Francisco","middleName":"","lastName":"Rivero","suffix":""},{"id":416939486,"identity":"c7b83dd0-6d4f-4945-9a0f-6e5203ecacd9","order_by":5,"name":"Rosario J. 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